In recent years, due to advances in virtualization technology, it has become possible to operate a plurality of virtual servers on a single physical server. By using such virtualization technology to operate a plurality of virtual servers on a single physical server, physical computer resources can be reduced and costs can be lowered.
Meanwhile, if a plurality of virtual servers are operated on a single physical server as mentioned above, physical computer resources are shared between a plurality of virtual servers; however, if physical computer resources are shared between a plurality of virtual servers, there is a problem in that the performance and availability of individual virtual servers are reduced.
Therefore, Cited document 1 discloses a technology for allocating, for occupied usage, specific physical computer resources (hereinafter called physical computer resources) to computer resources (hereinafter referred to as virtual computer resources) which are used as a current system of a virtual server, and for allocating, for shared usage, other physical computer resources to virtual computer resources of a standby system of the virtual server.